Curtain airbag device mounting structure and curtain airbag deployment method

A curtain airbag deployment method, the curtain airbag deployment method performable by a structure mounting a curtain airbag device including

• a rear-side garnish that is a part of a front pillar garnish and has a U-shape that opens to a front pillar side in a section orthogonal to a longitudinal direction, the U-shape being formed by a first side wall portion and a second side wall portion facing the first side wall portion,
• a curtain airbag stored in a folded state between the rear-side garnish and a pillar inner panel, and
• an inflator that activates to supply a gas to the curtain airbag upon detection or prediction of a collision of a relevant vehicle, the curtain airbag deployment method comprising:
• (a) holding the rear-side garnish in a state in which the rear-side garnish is apart from the front pillar via initial inflation of the curtain airbag caused by the activation of the inflator;
• (b) after the initial inflation, causing the curtain airbag to inflate and deploy from a gap between the rear-side garnish and the front pillar while pressing the first side wall portion and the second side wall portion of the rear-side garnish apart from each other;
• and
• (c) after the step of (b), inflating and deploying the curtain airbag toward an inner side of an interior of the vehicle from between the first side wall portion and the second side wall portion pressed apart from each other to inflate and deploy the curtain airbag in a curtain-like fashion over a side portion of the interior of the vehicle while withdrawing the rear-side garnish.